Lock



E. N. JACOBI Dec. 5, 1939.

LOCK

Filed April 4, 1938 bar and.

Patented Dec. 5, 1939 NITED STATES LOCK Edward N. Jacobi, Milwaukee, Wis, assignor to Briggs & Stratton Corporation,

Milwaukee,

Wis., a corporation of Delaware Application April 4, 1938, Serial No. 199,799

10 Claims.

This invention relates to improvements in cylinder locks, and refers particularly to locks of this type which are generally referred to as side bar locks.

In locks of this character, the cylinder or plug is locked against rotation by a locking bar projected radially by the tumblers from the side of the cylinder and into a locking recess in the casing. Heretofore, these locks were so constructed that the tumblers had a translating motion on a plane parallel to the key when in position in the cylinder, with the bar bearing against one side edge of each tumbler. Upon insertion of a proper key, notches in the side edges of the tumblers engaged by the car were aligned to receive the adjacent edge of the bar and permit its inward movement to a retracted unlocking position.

By virtue of the translating motion of the tumo s, all parts thereof, and particularly their engaged by the locking bar, moved the same distance, which motion was no greater than that capable of being produced by the bittings of the key. The little difierence in the heights of the key bittings and the inevitable lost motion and play which the tumblers have in their guides, very often resulted in objectionable interchangeability of keys. making it possible to have the same look respond to keys of different bittings at one or two tumblers.

With this and other objections of these past sidebar locks in mind, the present invention has as a major object to provide a lock of this character which the motion at the edge of the tumbler which engages the locking bar is greater than the motion of that portion of the tur-zbler *ngaged by the key. In other words, it is a porn e or" the present invention to multiply the propelled motion of the tumblers in its effect upon the locking bar.

To this end, the present invention contemplates a change in the construction of locks of this character whereby the tumblers instead of having a translating motion are mounted to rock about pivots so located with respect to the side the key slot that the key contacts the tumblers at points substantially midway between theirpivots and their engagement with the locking bar.

it is also an object of this invention to mount the tumblers in such a manner with respect to th locking bar that inward force applied to the in 1g bar has no turning moment efiective on the tumblers.

Another object of this invention is to so con-' locking positions permitting inward movement of the bar.

Another object of this invention is to so construct a lock of the character described that while each tumbler is assembled with the cylinder through a slot opening to the side of the cylinder, strength to resist forced attempts to twist the cylinder is provided by a substantial body of torsional stress resisting material at all cross sections of the cylinder.

A further object of this invention is to so construct the lock that the transverse slots which receive the tumblers also accommodate the tumbler springs acting on the tumblers to thereby simplify the assembly of the lock.

With the above and other objects in View which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawing illustrates one complete example of the physical embodiment of the invention constructed in accordance with the best mode so far devised for the ractical application of the principles thereof, and in which: Figure 1 is a top View of a lock constructed in accordance with this invention, the casing and part of the cylinder being broken away to illustrate structural details;

Figure 2 is a cross sectional view through the lock taken on the plane of the line 2-2 in Figure 1;

Figure 3 is a View similar to Figure 2, but showing the tumbler in its operative or looking position to which it moves upon withdrawal of the key; and

Figure 4 is a detail longitudinal sectional view through the cylinder taken on the plane of the line 44 in Figure 1.

Referring now particularly to the accompanying drawing in which like numerals indicate like parts, the numeral 5 designates the casing of the lock, which may be of any desired construction and may form part of a mechanism with which the lock is used, as for instance, the door handle of an automobile. The casing has a bore 5 to receive a cylinder 1 and has diametrically opposite recesses or grooves 8 to receive a locking bar 9 projectable from the side of the cylinder.

Projection of the locking bar into either one,

of the grooves 8 secures the cylinder against rotation. In the present instance, two grooves are provided so as to permit the key to be withdrawn in the unlocked as well as the locked position of the cylinder.

Rotation of the cyl nder is imparted to the mechanism to be actuated by means of an eccentrically disposed driving lug or pin l0 projecting from its inner end; and endwise motion of the cylinder in the casing is restrained by a lug (not shown) carried by the casing and engaging in the annular portion ll of a bayonet slot near the: inner end of the cylinder.

means whereby the cylinder is removably held in its casing, form no part of this invention and ar therefore not shown in detail.

The locking bar 9 is sidewise movable in a slot l2 opening to the side of the cylinder. The slot I2 is radial to the axis of the cylinder, and the locking bar 9 is yieldingly urged inwardly by springs l3. Although the specific manner in which the springs l3 apply their force to the locking bar may be varied, it is preferable to confine the same within the cylinder, and to this end, the locking bar has lugs 14 projecting from its opposite ends, and the springs engage these lugs and are retained in position by transverse supports l5 secured in the cylinder across the ends of the slot l2.

The inner longitudinal edge of the locking bar is V-shaped, as shown. and is disposed transversely to the plurality of plate tumblers l6. Each tumbler is positioned in an individual transverse slot I! extending inwardly from the bottom of an open recess I? which opens to the surface of the cylinder at right angles to the slot l2. 'Ihese'transverse tumbler receiving slots connect with the slot l2 and also open to a keyway l8 which extends longitudinally into the cylinder from its front end and is disposed at right angles to the radial plane upon which the bar moves.

All of the tumblers are pivotally mounted on a pin IS inserted into a bore 20 extending longitudinally into the cylinder from its inner end. The axis of the pivot pin l9 lies on the plane of the locking bar. Hence, inward force applied tothe locking bar and opposed by its engagement with the adjacent edges of the tumblers l6 imparts no turning moment to the tumblers.

It is to be observed that the keyway and consequently the points of contact between the tumblers and the bittings of a key 2| in position in the keyway lie substantially midway between the pivotal axis and the peripheries of the tumblers which engage the locking bar. Motion imparted to the tumblers by the key thus is multiplied at the peripheries of the tumblers which engage the locking bar, and in this manner, one of the primary objections of past side bar locks is entirely overcome.

Each tumbler is yieldingly urged to turn about its pivotal mounting toward the keyway by a tumbler spring 22. These springs are conveniently held in proper assembled relationship with respect to their tumblers by being received in pockets 2?! formed as part of the tumbler receiving transverse slots I! in a manner to be hereinafter described.

A tit 23 on each tumbler engages in the adjacent end of its spring and the opposite ends of the springs which bear against the adjacent side wall 23 of the recess I'! are held in place by a pin 26. The pin 24 extends longitudinally of the cylinder across the spring receiving pockets and is held in place by having its ends disposed in sockets 25 where it is secured by swedging one wall of each socket over the pin, as shown.

The edges of the tumblers, which are engaged by the V-shaped inner edge of the locking bar The manner in which rotation of the cylinder is utilized to effect the desired locking function and the details of the have notches 26 to receive the inner edge of the locking bar. The location of these notches 26 on the various tumblers varies in accordance with the bittings of the key to which the tumblers are fitted so that when a proper key is in place, all of the notches 26 are in alignment with the locking bar to allow its springs l3 to press it inwardly to an unlocked position.

With the bar retracted in this manner, the

cylinder is free to be turned and upon withdrawal of the key, which can only take place when the cylinder is either in its locked or unlocked position of rotation, the tumblers actuated by their springs 22 push the locking bar outwardly into engagement with a locking groove 8.

Those portions of the tumbler edges which engage the locking bar to hold the same in its locked position, as shown in Figure 3, are preferably straight so that by contacting the adjacent side wall 21 of the recess l1, their spring propelled motion is limited. It is to be observed that the side walls 2'! and 23' of the open recess I1 continue inwardly to form end walls for the transverse tumbler slots IT.

The remaining parts of these tumbler edges are curved and concentric to the pivotal axis of the tumblers so that each tumbler is freely movable from and toward its operative locking position without imparting any motion to the locking bar even though the tumblers are carried past their unlocked positions as by the insertion of an improper key, or as in the passage of higher bittings on the key during its insertion or withdrawal.

It is important to observe that the cylinder is so designed that in cross section there is sufllcient Iv metal at each and every point along its length to withstand any torsional stress that might be applied at its front end. This is accomplished by having solid walls of metal opposite the openings in the cylinder formed by the radial slot l2 and the open recess I1, and by providing solid metal webs 28 between the tumbler slots. The outer edges of these webs 28 having reentrant grooves in their opposite sides to provide shoulders which define the pockets 22' in which the springs are received, it being noted that the diameter of the springs is greater than the thickness of the tumblers.

From the foregoing description taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the art that this invention corrects one of the objections not only of past side bar looks, but of all cylinder locks wherein the inevitable lost motion which the individual tumblers have interferes with the accuracy and security of the look, by multiplying the key propelled motion of the tumblers in its locking eifect, and that a simpler more accurate construction is provided by pivoting the tumblers as distinguished from past practice in which tumblers were guided to move with a translating motion.

What I claim as my invention is:

1. A lock of the character described comprising: a cylinder having a slot in its side; a locking bar movable in said slot; spring means mounted within the cylinder for pressing the bar inwardly; a plurality of lever tumblers; a pivot for the tumblers lying in the plane of movement of the bar; each of said tumblers having an edge formed as an arc concentric to the pivot and another edge substantially radial to the pivot axis; said cylinder having a key slot adapted to receive and guide a key in position to have its bittings intersect and contact the substantially radial edges of the tumblers between the tumbler pivot and the concentric edges of the tumblers; said tumblers having V-shaped notches in their concentric edges adapted to be aligned by the bittings of a proper key to receive the side bar and enable the springs to press the same inwardly to an inoperative position, and arranged to produce an outward component of force on said locking bar to return it to operative position upon rotation of the tumblers when the key is withdrawn and upon the insertion of an improper key.

2. In a side bar lock of the character described: a cylinder having a radial slot; a locking bar mounted in said slot; a plurality of plate tumblers within the cylinder; means for pivotally mounting said plate tumblers with one edge of each tumbler bearing against the locking bar, said edge of each or" the tumblers having a V- shaped notch pointing toward said pivotal mounting and adapted to be aligned by a properly bitted key to permit inward movement of the locking bar; and bearing edges on the tumblers for the bitted key, said bearing edges being disposed between the pivot and the notched edges of the tumblers so that adjustments of the tumblers by the bittings of the key are multiplied at their notched edges.

3. In a side bar lock of the character described: a cylinder having a radial slot in one side and having a keyway lying on a plane disposed substantially at right angles to the slot; a side bar movable in said slot; spring means disposed within the cylinder slot for yieldingly urging the side bar inwardly; a plurality of tumblers disposed within the cylinder; means for pivotally mounting the tumblers on an axis so located that the keyway lies between it and the side bar; edges on the tumblers formed as arcs struck from the tumbler pivot and having notches to receive the inner edge of the side bar upon movement of the tumblers by a properly bitted key to positions at which all of the notches are aligned, and cooperating surfaces on the tumblers at said notches and the side bar disposed at an angle to the plane passing through the pivotal mounting and the center of the bar engageable upon rotation of the tumblers in a direction away from the positions at which their notches are aligned to force the bar outwardly away from the tumblers.

4. In a side bar lock of the character described: a one-piece cylinder having a longitudinal key slot; and having a bearing hole for the reception of a tumbler pivot extending parallel to the key slot; said cylinder also having transverse slots to receive tumblers, which slots have end walls parallel to the planes defined by the sides of the key slot and have one open side and a closed bottom under the edge of the key slot.

5. In a side bar lever tumbler lock of the character described: a one-piece cylinder having a longitudinal key slot and having a bearing hole for a tumbler pivot extending parallel to the key slot, said cylinder also having transverse slots for the reception of tumblers, said slots having end walls parallel to the side planes of the key slot and one open side and a closed bottom under the edge of the key slot; and said cylinder further having a radial slot parallel to the axis of the pivot bearing and intersecting the transverse tumbler receiving slots.

6. A lock of the character described comprising: a cylinder having transverse slots for the reception of plate tumblers; plate tumblers in said slots; a pivot pin extending longitudinally of the cylinder and crossing the transverse slots to form a pivot for the tumblers; said cylinder having a slot extending longitudinally of the cylinder and intersecting the tumbler slots on a plane passing through the axis of the pivot pin; and a locking bar movable in said slot and engaging the outer edges of the plate tumblers on a plane radial to the axis of the pivot so that inward force applied on the locking bar and against the tumblersproduces no turning moment upon the tumblers.

7. In a lock of the character described: a cylinder having a longitudinal keyway extending inwardly from its front end and having a radial slot substantially at right angles to the plane of the keyway and lying at one side or" the keyway; a locking bar movable in said radial slot; a plurality of lever tumblers within the cylinder with parts disposed on opposite sides of the keyway and with one edge engaging the locking bar; a pivot lying substantially on the plane of the radial slot for pivotally mounting all of the lever tumblers for swinging movement; said tumblers having their outer edges notched for the reception of the inner edge of the locking bar; individual springs acting on said plate tumblers to hold the same in positions at which their notches are out of line with the locking bar and the outer edges of the tumblers project the bar beyond the periphery of the cylinder; and key engaging surfaces on the tumblers engageable by the bittings of keys inserted into the keyway and so located that a proper key disposes the tumblers in positions at which all of the notches are in alignment with the locking bar.

8. In a lock of the character described: 9. cylinder having a plurality of transverse slots; tumblers received in said slots; a common pivot for all of said tumblers; individual coil springs for the tumblers, said springs having coils greater in diameter than the thickness of the tumblers and said slots being enlarged to receive the tumbler springs and guide the same, said slots having end walls forming abutments for the springs; and a spring retaining rod extending longitudinally of the cylinder across said slots in a position to hold the springs in engagement with the walls of the slots.

9. In a lock of the character described: a cylinder having a plurality of transverse slots with spaced end walls; tumblers in said slots; a common pivot for all of said tumblers; individual tumbler springs for the tumblers, said springs being located in the slots, and each spring being confined between its tumbler and the adjacent end wall of its respective slot to yieldingly urge the tumbler about its pivot toward the opposite end wall of the slot; and shoulders on the walls between the slots partially embracing and guiding the springs.

10. In a lock of the character described: a one piece cylinder having an open recess provided with spaced side walls; and spaced transverse walls extending across the recess from side wall to side wall to define transverse slots adapted to receive plate tumblers, said transverse walls having their outer edges spaced inwardly of the mouth of the open recess and their outer edge portions having reentrant grooves on opposite sides to form shoulders which define pockets for the reception of tumbler springs.

EDWARD N. JACOBI. 

